Internal-combustion engine



May 15, 1928.

' v 5., W. RUSHMORE INTERNAL COMBUSTION ENGINE Filed Jan. 30 1928 e 06 7 6 47 M ul i M K M T 0 BY W ATTOR N EY Patented May. 1 5, 1928.

UNITED S TES.

PATENTJLQFFICE.

SAMUEL w. ausnmonn, or rtsnmmnmnw'annsny. i "5 inrEnn L-commswrou Enema application med January so, 1928. Serial n 1, 50,424. F

My present invention concerns internal" combustion engines of'the type set forth in my "companion applications resulting in Patents Nos. 1,658,463 and 1,658,464. As

6 .explained in said patents, the improvements apply particularly to engines of ,the' prior art, wherein high compression is known to be highl 'desirable for efiiciency and econonr ytof uel consumption, but the nature offold and valves are on one side of the engine and the exhaust manifold and'valves on the other side of the engine. l While this type of engine is highly desirable because it permits the use-of large valves and for other reasons, it has been found to afford conditions particularly favorable-for detonation and hence least favorable for high compression. I

cylinder into a plurality oftchamb ers that are virtually separated at the instant of ignition, preferably employing two spark plugs for each cylinder, one in each of its compression'chambers. 'In No. 1,658,463, the separate chambers are preferably located symmetrically on opposite sides of the cylinder,

each overlapping a relatively small area of the piston,'on opposite sides thereof. With this arrangement and with the explosion substantially simultaneous in each chamber.

the pressures initially applied to the headof the piston will be approximately equal on'opposite sides'of-the line of thrust.

In No. 1,658,464, most of the compression space of each cylinder is localized adjacent the inlet valve, leaving only a small compression spaceadjacent the exhaust valve,

but as in the other case, the head is shaped so that these two chambers arevirtually.

separated at the instant of ignition.

While, broadly considered, my present invention is applicable in either of'these cases.

I prefer to combine it with the features of .being soft and tarry, is s mple squeezed along and ejectedbefore it has time to form the latter case, No. 1,658,464. In this form the exit from the cylinder to the exhaust Both said companion cases contemplate splittingf up the compression space ofeachvalve may be of substantially reduced cross-' section and may even show very substantial resistance to escape of the exhaust. Very considerable resistance is of relatively small effect because the major part of scavengingof the cylinder occurs as soon as the exhaust valve opens and releases part of-the exhaust gas. The rema nder of thefscavenging during the exhaust stroke requires relatively low velocity outflow. Conthe highpressure sequently, material throttling or resistance of the exhaust outlet willicause only a slight effect upon the brake horsepower of the 7 engine, and this" is more than compensated for 'b'ythe efi'ect of such throttling resistance,

in keeping the combustible charge away i from the hot' exhaust valve, thus making it possible to raise the compression to a very high figure without any danger of detona tlon.

only at the instant the piston is at the top of its stroke, no moving parts other than the piston are necessary for thus separating thc'co'mpr'ession spaces.- In both of my prior cases this is accomplished by forming the v periphery.

' My present invention concerns an improvement whichconsists in providing for the minimum clearance zone, a stepped or bafile zone in the nature of-interfitting ele- As. detonation is caused and completed vated and depressed surfaces on the piston head and cylinder head. Preferably substantial parallelism is maintained for the stepped construction of my present invention, as for the plane construction,elected for illustration insaid prior cases.

I have determined by actual experiment,

-' that even with the baflle arrangement, the

permissible clearance between surfaces may 'be reduced to a veryfew thousandthsof an inch without danger that carbon deposits will cause the piston head to' pound the cylinder head. If the carbon were suddenly introduced, thev pounding naturally would .be severe, but the so-called carbon is initially a soft, gummy deposit, consisting mainly of silica from the road dust with some carbon and oil. The deposit is gradual and,

i a solid. Consequently,

' the compression space Earallel surfaces.

adjacent the inlet valve, will become chilled and incapable of cutting a passage through the carbon to perinit passage of a detonating wave over to the the accompanying drawings, in

exhaust valve passage, even in case the latter the chambers 13 and other so as to partially overlap the head of should contain an explosive charge.

The abovea'nd other features of my invention will be more fully understood from the following description in connection with which axial section trans- Fig. 1 is a vertical vers'ely of an internal combustion engine 0 the T-head type, havingmy invention embodied therein, the section being on the line 1-1, Fig. 2;

Fig.2 is a top plan view of the cylinders and valves with the cylinderhead removed.

In these drawings, the parts of the engine necessary to an invention are shown as comprising the cylinder 1, provided with a water-jacket 2, formed with an intake 5, controlled by intake valve 6, an'exhaust 3 controlled by an exhaust valve 4,'a piston 7 in the cylinder and, in operative relation to the above parts, a cylinder head 8, provided with a waterjacket9 and having-mounted therein spark plugs 10, 11.

piston 7 on dead center at the 'As shown in Fig. 1, in the position of the upper end of the compression strokeait has all the central area of its upper face 7 closely confronted by a broad lower surface 8 of the cylinder head 8. maybe reduced to approximately the minimum practically permissible by conditions of ordinary operation. The important feature is that .this broad central .zone of minimum-clearance is in -a different plane .from the piston surfaces 8 and 8 that are I adjacent the inlet and exhaust chambersre spectively,, so .erably the piston head, has this'zone projecting into a recess'in the other. This arrangement affords transverse ribs on the cylinder head extending entirely acrossthe piston head, one, 8 adjacent the inlet 14 and the other 8 adjacent the exhaust. By this arrangement, a pro-ignition or detonation wave would have to travel'a greater total distance than in my prior arrangement, besides encountering four corner turns giving four baflling, cooling impacts, progressing from one chamber to the other across the piston head. This makes certain that no such wave can get across, even though the minimum clearance be considerable. In this understanding of my present The clearance between 7 and 8' that one of the elements, prefp separate spark plug for as large and of as low resistance as may be On the other hand, the exhaust is of small volume and throttled outlet desiredi valve chamber 13. afiords a small somewhat from the" cylinder.

As indicated in dot and dash lines, Fig. 2,

the piston 7. The area of the overlap of eachchamber may vary considerably fromthat shown as may also the volumes of the chambers, but always there is a widearea f' zone of the mterfitting small clearance surfaces between them, when the piston is in the posit-ion shown. In the drawing, the largest overlap, that 'ofrinle't valve chamber 14, is less than one-third of the diameter and less than one-sixth of the area of the piston head.

, It results from the above relation of parts that the two chambers 13, 14, constitute a single compression space in so far as concerns density and degree of compression during the compression stroke,'but the explosive mixture goes mainly into 14 and, so far as concerns burning of the charge and particularly asconcerns propagation of a detonating wave, t

hotexhaust'valve 4 by the piston when at the upper limit of its stroke.

- For instance, assuming a comprossionratio of, say, 5 to' 1, the combustible charge in the intake chamber will be 20 parts exhaust gas and eighty parts fresh mixture, but the exhaust chamber, and removed from charge, will contain nothing but burnt gas he maincompression 14 extend'toward each I being an isolated pocket the stream of incoming until the beginning of the compression stroke and at the end of compression of the space will be A; exhaust and A of the space-all ex-. haust, making approximately thirty-six arts of exhaust gas to sixty-four parts of fresh charge. As there can be very little tubulence, in my elongated and restricted exhaust chamber, it is probable that most of the exhaust is crowded to the farthest end, and there, whore the exhaust valve-will be the hottcst,.there is nothing-but exhaust gas. Therefore, even if athin sheet of flame should enter the exhaust chamber, the combustion could not by any chance approa ch; detonating violence.

from '14 and the separation is such that a.

13 and14 may be desirable for causing synchronized sparks in the two chambers to initiate combustion in both parts of the charge, if the proportions and conditions of Operation are such that 13 will contain a burnable charge.v In any event, actual experience shows that by my invention there is nopossibility of ,backfiring or detonation, but onlycincreasin'g efliciency and smooth running with compression ratiosof to 1 and 6 to 1, ratios that i are unheard oi in present-day automobile engines of any other t pe.

By my above descri ed invention, I am enabled to so increase the compre sion that with the larger valves permitted by the T- L'An internal combustion engine, the-- high-compression, T-head type, having a valved inlet passage for intake of an unignited charge located on 'one side of said head and a, valved exhaust outlet chamber located in the opposite side; said engine including also a-cylinder, piston and cylinder head arranged tov afford a plurality of compression chambers, separated by areas of small clearance, said areas including transverse barrier, elements extending entirely across. the cylinder head and the piston adaptedto overlap and battle intercommuni- "cation between said chambers when the pis ton is. at the-"upper endfof the compression stroke, one of said compression chambers in- .cluding the inlet on-one side of-the barrier and theother including vthe exhaust outlet on the other side of the barrier.

2. An internal combustion engine, of the high-compression, T-head type, having a valved inlet passage for intake of an unignited charge located on one side of said head and a valved exhaust out-let chamber located inthe oppositeside; said engine including also a cy inder,piston and cylinder head arranged to afford a plurality of compression chambers, separated by areas of small clearance, said areasincluding transverse barrier elements extending entirely across .the cylinder head and the piston adapted" g to overlap and battle intercommunication between said chambers when the piston is at the upper end of the compression stroke, one of said compression chambers includingthe inlet on one side of the barrier and the other including the exhaust outlet on the other side of the barrier, in combination with a spark-plug in operative relation to-said inlet chamber.

31 An internal combustion engine, of the high-compression, T-head type, having a. valved inlet passage for intake of an unignited charge located on one side of said head and a valvedrexhaust outlet chamber located in the opposite side, said engine outlet on the other side of the barrier, in

combination with spark plugs for each of said chambers.

"4. An internal combustion engine, of the high-compression, T-head type, having a valved inlet passage for intake of an unignited charge located on one side of said .head and a valved exhaust outlet chamber located in the opposite side; said engine including also a cylinder, piston and cylinder head arranged to afford-- a plurality of compression chambers, separated bytransverse barrier elements aiiording areas of small clearance extending entirely across the cylinder head and the piston and interfitting when the piston.is at the upper end of the compression stroke, one of said compression chambers including the inlet and the other including the exhaust outlet, the chamber that includes the inlet being of large volume to afi'ord most of the compression space, while the: one inc-luding theexhaust outlet isrelatively small and has communication with the cylinder space through an exhaust outlet passagethat is smaller than the inlet passage.

. 5; An internal combustion engine, of the high-compression type, having a valved in let passage for intake of an unignitcd charge located on one side of said head and a. valved exhaust outletchamber located in the opposite side; said engine including arranged to afford a. plurality of compression chambers, separated by transverse barrierelements affording areas of small clear-. ance extending entire1y-across the cylinder head and the piston and-'interfitting when the piston is at the upper end of the compression stroke, one of said compression chambers including the inlet and the other including the, exhaust outlet, the chamber that includes the inlet being of large volume to afi'ord most of the compression space, While the one including the exhaust outlet is' relatively small and has communication with the cylinder space through an exhaust outlet passage that is smaller than the inlet passage, in combination with a sparkplug in operative relation to said inlet. chamber.

6. Ap internal combustion engine, of the high-compression type, having a valved inance extending entirely across the cylinder head and the piston and interfitt-ing when space,

let passage for intake of an unignited" located on one side of said head and charge a valved exhaust outlet. chamber located in the opposite a cylinder, ,piston' and cylinder head arranged to afford a plurality of compression chambers, separated by transverse barrier elements affordingareas of small clearthe piston is at the upper end of the compression stroke, one of said compression chambers including the inlet and the other including the exhaust outlet, the chamber "that includes the inlet being of large vol,

ume to afford most of the compression outlet is relatively small and has communication with the cylinder space through an exhaust outlet that is smaller than the inlet, in combination with spark plugs for each ofgsaid chambers. a

7. An internal combustion engine inclhding cylinder,

sion, and having inlet and exhaust valves in separate inlet and exhaust chambers respecbers respectively pression,

tively located on opposite sides of the cylinder, whereby the exhaust valve is remote from and is not cooled by the intake charge;

7 said valve chambers being adapted to afford ,two'c'ompression spaces that are separated from each other by an area of small working clearance between cooperating surfaces in the cylinder head and the piston respecremote from and is not cooled by the intake charge; said valve chambers. being adapted to afford two compression spaces that are separated from each other by an area of small working clearance between cooperating surfaces in the cylinder head and the side; said engine including also,

while the one including the exhaust head and piston of diameter, stroke and clearance affording high compreslocated on opposite sides of the cylinder, whereby the exhaust valve is piston respectively,

letes its compression stroke, ing surfaces including a'transversely extending projection and a recess into which the projection fits, theprojection 'bein on the piston head .andthe recess being 1n registry therewith in the surface of the cylinder :head.

An internal combustion engine including cylinder, head and piston of diameter, stroke and clearance affording high compression, and having inlet and exhaust when the piston com- ,the cooperatvalves in separate inlet and exhaust chambers respectively of the cylinder, whereby the exhaust valve is remote from and is not cooled by the intake charge; said valve chambers being adapted to' afford two compression spaces that are separated from each other by an area of small working clearance between cooperating surfaces in the cylinder head and the piston respectively, when the piston located on opposite sides' completes its compression stroke, the co-' operating surfaces including a transversely extending projection and a recess into which the projection fits, one being on the piston head and the other on the cylinder head, in combination with a spark plug in operative relation to said inlet chamber. 10. An internal combustion engine including cylinder, head and piston of diameter, stroke and (clearance affording high com pression, and having inlet and exhaust valves in separate inlet and exhaust chambers respectively located on opposite sides of the cylinder, whereby the exhaust valve isremote from and is not cooled by the intake charge; said valve chambers being adapted to afford two compression spaces that are separated from each other by an area of small working clearance between cooperating surfaces in the cylinder head and the piston respectively, when the piston completes its compression stroke, the cooperating surfaces including a transversely extending projection and a recess into which the projection fits, one being on the piston head and the other on the cylinder head, in combination with spark plugs for each of said chambers. 4

Si ned at' Miami in the county of Dade and state of- Florida this 24th day of January, A. D. 1928. I SAMUEL \V. RUSHMORE:

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